Data acquisition in well during production and drilling have occurred for many years. In the production sector of the exploration and production of hydrocarbons, the use of downhole gauges for production and reservoir evaluation are done using permanent and retrievable systems.
The retrievable systems are normally deployed inside production tubing using an electrical cable that transmits information from the well in real time to the surface as the system is pulled from the bottom of the sell to the surface, logging the entire well for data.
There are also permanently deployed gauges and semi permanent gauges. The permanent gauges use a cable mounted on the outside of the production tubing from the surface to where the gauge is located in the well. The gauges transmit data in real time continuously. If the cable is cut then the gauge is no longer connected to the surface and no data is transferred to the surface. The cable deployment is also very complicated and can cause the customer to have to go in the well to fish the system if the cable is not flush to the production tubing.
There are semi-permanent gauges where the system seats in a side pocket mandrel inside the well. The gauge collects data and stores the data in memory. When the operator wants data he retrieves the gauge from the well. The customer uses specialty equipment to retrieve and install the gauge. There is a potential for the gauge to fall from the retrieval equipment and go to the bottom of the well. Also the gauge may not come out of the side pocket gauge.
A new system where the gauge does not to need to be retrieved from downhole and does not use downhole cables has been developed to decrease potential failures due to cut cables and complications in retrieving gauges from downhole.